I know this is old hat as far as most of us are concerned, but it still hits me when I hear it. This weekend alone I've heard that people left sim because they felt unwanted. Tonight I had a friend say every time she posted to someone, they walked off 2-3 minutes later. This sort of thing absolutely kills me to hear because I have been there! Thankfully people responded when I pointed it out and my whole experience here was turned around.
It shouldn't get that far though. Just from a fellow sim member to another, please make sure you acknowledge people around you! You never know what amazing role player we may lose because you didn't want to talk to someone you didn't know or someone new. Really it only takes a second to pause and type out "Smiles at the new person as they walk by". Yes, that is tiresome to do to everyone you see, but if they are standing alone, what does it hurt?